U.S. patent application number 10/827869 was filed with the patent office on 2004-10-21 for apparatus, method and program for physical state controller.
This patent application is currently assigned to International Business Machines Corporation. Invention is credited to Okano, Hiroyuki, Yoda, Kunikazu.
Application Number | 20040210324 10/827869 |
Document ID | / |
Family ID | 33157078 |
Filed Date | 2004-10-21 |
United States Patent
Application |
20040210324 |
Kind Code |
A1 |
Yoda, Kunikazu ; et
al. |
October 21, 2004 |
Apparatus, method and program for physical state controller
Abstract
For determination as to whether there is a possibility that
temperature control satisfying conditions according to an upper
limit LH_i and a lower limit LL_i of the annealing control
temperatures of annealing object steel sections i will be realized
under restrictions on limit values U and D of the control
temperature increase and decrease rates, computation is performed
without using dynamic programming requiring an enormous amount of
data on a continuous annealing line of a steelwork. Annealing
object steel sections in an annealing object steel band 12 to be
computed are assigned numbers 1, 2, . . . , n in order from the
first time division in the direction of movement. T_i is a time
required to pass the annealing object steel section i through a
predetermined point at which the steel section undergoes
temperature control. LH_1=LL_1=b is given. X_i=[IL_i-D*T_i,
IH_i+U*T_i] is computed. When X_ L_i.sup.1 f, Y_i=X_i L_i. When X_i
L_i=f, Y_i=X_i. Y.sub.--i is computed from i=1 to i=n in ascending
order.
Inventors: |
Yoda, Kunikazu;
(Kanagawa-ken, JP) ; Okano, Hiroyuki; (Tokyo-to,
JP) |
Correspondence
Address: |
MOSER, PATTERSON & SHERIDAN L.L.P.
595 SHREWSBURY AVE, STE 100
FIRST FLOOR
SHREWSBURY
NJ
07702
US
|
Assignee: |
International Business Machines
Corporation
Armonk
NY
|
Family ID: |
33157078 |
Appl. No.: |
10/827869 |
Filed: |
April 20, 2004 |
Current U.S.
Class: |
700/33 ; 700/11;
700/153; 700/207 |
Current CPC
Class: |
G05B 5/01 20130101; G05D
23/1917 20130101 |
Class at
Publication: |
700/033 ;
700/011; 700/153; 700/207 |
International
Class: |
G06F 015/00; G05B
011/01; G06F 009/40; G06F 009/30; G06F 019/00; G05B 013/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 21, 2003 |
JP |
2003-115246 |
Claims
1. A physical state control purpose information computation
apparatus which computes information used by a physical state
controller, a control time period of a finite length being divided
into a plurality of consecutive time divisions, the physical state
controller controlling a physical state of a
control-processing-object material, a limited physical state range
relating to the physical state of the control-processing-object
material being set in each time division, the physical state
controller changing the physical state of the
control-processing-object material at a rate within the
corresponding limit control rate range and simultaneously
controlling the physical state of the control-processing-object
material so that the physical state of the
control-processing-object material is within the limited physical
state range in the time division, said apparatus comprising:
time-division-basis reachable physical state range computation
means of computing a reachable physical state range reachable by
the time the given time division ends on the basis of the physical
state control range at the beginning of the given time division and
the limit control rates of the physical state controller;
time-division-basis physical state control range computation means
of computing a physical state control range at the beginning of the
time division next to the given time division on the basis of the
reachable physical state range at the end of the given time
division and the limited physical state range in the next time
division; and overall physical state control range computation
means of designating the time divisions in order from the first
time division to the last time division in the control time period
and making each of said time-division-basis reachable physical
state range computation means and said time-division-basis physical
state control range computation means repeat executing its
processing to obtain physical state control ranges at the
beginnings of all the time divisions.
2. A physical state control purpose information computation
apparatus which computes information used by a physical state
controller, a control time period of a finite length being divided
into a plurality of consecutive time divisions, the physical state
controller controlling a physical state of a
control-processing-object material on the basis of conditions
relating to the physical state of the control-processing-objec- t
material in each of the time divisions through the entire control
time period, the following definitions being given (information
about n, b, e, LL_i, LH_i, D, and U being given, each index on the
right-hand side of "_" representing a number): (a1) n: the total
number of time divisions constituting the control time period (a2)
i: the number of each time division in the control time period when
the time divisions are successively assigned numbers 1, 2, . . . ,
n in order from the first time division in time series (a3) b: the
value of the physical state of the control-processing-object
material at the beginning of the number-1 time division (a4) e: the
value of the physical state of the control-processing-object
material at the end of the number-n time division (a5) LL_i: a
lower limit value of the physical state of the
control-processing-object material in the number-i time division
(a6) LH_i: an upper limit value of the physical state of the
control-processing-object material in the number-i time division
(a7) L_i=[LL_i, LH_i], L_(n+1)=[LL_n, LH_n](a8) D: a limit
heightening rate when the physical state of the
control-processing-object material is heightened (a9) U: a limit
lowering rate when the physical state of the
control-processing-object material is lowered (a10) *: a
multiplication operator (a11) T_i: the length of the number-i time
division (a12) IL i: a lower limit of the physical state of the
control-processing-object material reachable by the time the
number-i time division begins (a13) IH_i: an upper limit of the
physical state of the control-processing-obje- ct material
reachable by the time the number-i time division begins (a14)
I_i=[IL_i, IH_i], I.sub.--1=[b, b]=b (a15) X_i=[LL_i-D*T_i,
IH_i+U*T_i](a16) Y_i=X_i L_i when X_i L_i.sup.1 f (a17)Y_i=X_i when
X_i L_i=f (a18) I_(i+1)=Y_i L_(i+1) when Y_i L_(i+1).sup.1f (a19)
I_(i+1)=Y_i when Y_i L_(i+1)=f, said apparatus compr first
processing means of computing X_i from I_i on the basis of said
(a15) with respect to a given i; second processing means of
computing Y_i on the basis of the result of computation by said
first processing means and said (a16) and (a17) with respect to the
given i; third processing means of computing I_(i+1) on the basis
of the result of computation by said second processing means and
said (a18) and (a19) with respect to the given i; fourth processing
means of storing, as information, I_(i+1), i.e., the result of
computation by said third processing means, with respect to the
given i; and first number designation means of making each of said
first to fourth processing means execute its processing with
respect to the values of i in ascending order from i=1 to i=n.
3. The physical state control purpose information computation
apparatus according to claim 2, wherein the following definitions
are given: (b1) s.sub.--1=b (b2) s_(i+1)=s_i when s_i I_(i+1) (b3)
s_(i+1)=IL_(i+1) when s_i<IL_(i+1) (b4) s_(i+1)=IH_(i+1) when
s_i>IH_(i+1), said apparatus further comprising: fifth
processing means of computing s_(i+1) on the basis of said (b2) to
(b4) with respect to the given i; sixth processing means of
storing, as information, s_(i+1), i.e., the result of computation
by said fifth processing means, with respect to the given i; and
second number designation means of making each of said fifth and
sixth processing means execute its processing with respect to the
values of i in ascending order from i=1 to i=n-1.
4. The physical state control purpose information computation
apparatus according to claim 3, wherein the following definitions
are given: (c1) t_(n+1)=e, (c2) Z_i (:=[ZL_i,
ZH_i])=[t_(i+1)-U*T_i, t_(i+1)+D*T_i](c3) t_i=s_i when s_i Z_i (c4)
t_i=ZL_i when s_i<ZL_i (c5) t_i=ZH_i when s_i>ZH_i, said
apparatus further comprising: seventh processing means of computing
Z_i from t_(i+1) on the basis of said (c2) with respect to the
given i; eighth processing means of computing t_i on the basis of
the result of computation by said seventh processing means and said
(c3) to (c5) with respect to the given i; ninth processing means of
storing, as information, t_i, i.e., the result of computation by
said eighth processing means, with respect the given i; and third
number designation means of making each of said seventh to ninth
processing means execute its processing with respect to the values
of i in descending order from i=n to i=1.
5. The physical state control purpose information computation
apparatus according to claim 2, wherein the
control-processing-object material is one of a solid, a liquid and
a gas, or a combination of any of the solid, liquid and gas.
6. The physical state control purpose information computation
apparatus according to claim 2, wherein the physical state is a
dynamic state, an optical state, a thermodynamic state or an
electromagnetic state.
7. The physical state control purpose information computation
apparatus according to claim 2, wherein the
control-processing-object material is a metal and the physical
state is temperature.
8. The physical state control purpose information computation
apparatus according to claim 7, wherein the metal is steel to be
annealed; the steel to be annealed is formed as a continuous member
in which a plurality of lengthwise sections having different
annealing temperature upper and lower limits are connected in
series in the direction of movement, which is moved at a constant
speed, and which undergoes annealing at a predetermined position in
the direction of movement; and LH_i and LL_i correspond to the
upper limit temperature and the lower limit temperature in
annealing on the number-i lengthwise section of the continuous
member.
9. A physical state control purpose information computation method
of computing information used by a physical state controller, a
control time period of a finite length being divided into a
plurality of consecutive time divisions, the physical state
controller controlling a physical state of a
control-processing-object material, a limited physical state range
relating to the physical state of the control-processing-object
material being set in each time division, the physical state
controller changing the physical state of the
control-processing-object material at a rate within the
corresponding limit control rate range and simultaneously
controlling the physical state of the control-processing-object
material so that the physical state of the
control-processing-object material is within the limited physical
state range in the time division, said method comprising: a
time-division-basis reachable physical state range computation step
of computing a reachable physical state range reachable by the time
the given time division ends on the basis of the physical state
control range at the beginning of the given time division and the
limit control rates of the physical state controller; a
time-division-basis physical state control range computation step
of computing a physical state control range at the beginning of the
time division next to the given time division on the basis of the
reachable physical state range at the end of the given time
division and the limited physical state range in the next time
division; and an overall physical state control range computation
step of designating the time divisions in order from the first time
division to the last time division in the control time period and
repeating executing each of said time-division-basis reachable
physical state range computation step and said time-division-basis
physical state control range computation step to obtain physical
state control ranges at the beginnings of all the time
divisions.
10. A physical state control purpose information computation method
of computing information used by a physical state controller, a
control time period of a finite length being divided into a
plurality of consecutive time divisions, the physical state
controller controlling a physical state of a
control-processing-object material on the basis of conditions
relating to the physical state of the control-processing-object
material in each of the time divisions through the entire control
time period, the following definitions being given (information
about n, b, e, LL_i, LH_i, D, and U being given, each index on the
right-hand side of "_" representing a number): (a1) n: the total
number of time divisions constituting the control time period (a2)
i: the number of each time division in the control time period when
the time divisions are successively assigned numbers 1, 2, . . . ,
n in order from the first time division in time series (a3) b: the
value of the physical state of the control-processing-object
material at the beginning of the number-1 time division (a4) e: the
value of the physical state of the control-processing-object
material at the end of the number-n time division (a5) LL_i: a
lower limit value of the physical state of the
control-processing-object material in the number-i time division
(a6) LH_i: an upper limit value of the physical state of the
control-processing-object material in the number-i time division
(a7) L_i=[LL_i, LH_i], L_(n+1)=[LL_n, LH_n](a8) D: a limit
heightening rate when the physical state of the
control-processing-object material is heightened (a9) U: a limit
lowering rate when the physical state of the
control-processing-object material is lowered (a10) *: a
multiplication operator (a11) T_i: the length of the number-i time
division (a12) IL_i: a lower limit of the physical state of the
control-processing-object material reachable by the time the
number-i time division begins (a13) IH_i: an upper limit of the
physical state of the control-processing-obje- ct material
reachable by the time the number-i time division begins (a14)
I_i=[IL_i, IH_i], I.sub.--1=[b, b]=b (a15) X_i=[IL_i-D*T_i,
IH_i+U*T_i](a16) Y_i=X_i L_i when X_i L_i.sup.1 f (a17) Y_i=X_i
when X_i L_i=f (a18) I_(i+1)=Y_i L_(i+1) when Y_i L_(i+1).sup.1f
(a19) I_(i+1)=Y_i when Y_i L_(i+1)=f, said method comprisi a first
processing step of computing X_i from I_i on the basis of said
(a15) with respect to a given i; a second processing step of
computing Y_i on the basis of the result of computation in said
first processing step and said (a16) and (a17) with respect to the
given i; a third processing step of computing I_(i+1) on the basis
of the result of computation in said second processing step and
said (a18) and (a19) with respect to the given i; a fourth
processing step of storing, as information, I_(i+1), i.e., the
result of computation in said third processing step, with respect
to the given i; and a first number designation step of executing
each of said first to fourth processing steps with respect to the
values of i in ascending order from i=1 to i=n.
11. The physical state control purpose information computation
method according to claim 10, wherein the following definitions are
given: (b1) s.sub.--1=b (b2) s_(i+1)=s_i when s_i I_(i+1) (b3)
s_(i+1)=IL_(i+1) when s_i<IL_(i+1) (b4) s_(i+1)=IH_(i+1) when
s_i>IH_(i+1), said method further comprising: a fifth processing
step of computing s_(i+1) on the basis of said (b2) to (b4) with
respect to the given i; a sixth processing step of storing, as
information, s_(i+1), i.e., the result of computation in said fifth
processing step, with respect to the given i; a second number
designation step of executing each of said fifth and sixth
processing steps with respect to the values of i in ascending order
from i=1 to i=n-1.
12. The physical state control purpose information computation
method according to claim 11, wherein the following definitions are
given: (c1) t_(n+1)=e, (c2) Z_i (:=[ZL_i, ZH_i])=[t_(i+1)-U*T_i,
t_(i+1)+D*T_i](c3) t_i=s_i when s_i Z_i (c4) t_i=ZL_i when
s_i<ZL_i (c5) t_i=ZH_i when s_i>ZH_i, said method further
comprising: a seventh processing step of computing Z_i from t_(i+1)
on the basis of said (c2) with respect to the given i; an eighth
processing step of computing t_i on the basis of the result of
computation in said seventh processing step and said (c3) to (c5)
with respect to the given i; a ninth processing step of storing, as
information, t_i, i.e., the result of computation in said eighth
processing step, with respect the given i; and a third number
designation step of executing each of said seventh to ninth
processing steps with respect to the values of i in descending
order from i=n to i=1.
13. The physical state control purpose information computation
method according to claim 10, wherein the control-processing-object
material is one of a solid, a liquid and a gas, or a combination of
any of the solid, liquid and gas.
14. The physical state control purpose information computation
method according to claim 10, wherein the physical state is a
dynamic state, an optical state, a thermodynamic state or an
electromagnetic state.
15. The physical state control purpose information computation
method according to claim 10, wherein the control-processing-object
material is a metal and the physical state is temperature.
16. The physical state control purpose information computation
method according to claim 15, wherein the metal is steel to be
annealed; the steel to be annealed is formed as a continuous member
in which a plurality of lengthwise sections having different
annealing temperature upper and lower limits are connected in
series in the direction of movement, which is moved at a constant
speed, and which undergoes annealing at a predetermined position in
the direction of movement; and LH_i and LL_i correspond to the
upper limit temperature and the lower limit temperature in
annealing on the number-i lengthwise section of the continuous
member.
17. A physical state control purpose information computation
program for making a computer function as each of the means in the
physical state control purpose information computation apparatus
according to claim 1.
18. A physical state control purpose information computation
program for making a computer function as each of the means in the
physical state control purpose information computation apparatus
according to claim 2.
19. A physical state control purpose information computation
program for making a computer function as each of the means in the
physical state control purpose information computation apparatus
according to claim 3.
20. A physical state control purpose information computation
program for making a computer function as each of the means in the
physical state control purpose information computation apparatus
according to claim 4.
21. A physical state control purpose information computation
program for making a computer function as each of the means in the
physical state control purpose information computation apparatus
according to claim 5.
22. A physical state control purpose information computation
program for making a computer function as each of the means in the
physical state control purpose information computation apparatus
according to claim 6.
23. A physical state control purpose information computation
program for making a computer function as each of the means in the
physical state control purpose information computation apparatus
according to claim 7.
24. A physical state control purpose information computation
program for making a computer function as each of the means in the
physical state control purpose information computation apparatus
according to claim 8.
25. A physical state controller which controls a physical state of
a control-processing-object material on the basis of physical state
control ranges, I_i, s_i and/or t_i computed by the physical state
control purpose information computation apparatus according to
claim 1, I_i, s_i and/or t_i corresponding to time divisions i.
26. A physical state controller which controls a physical state of
a control-processing-object material on the basis of physical state
control ranges, I_i, s_i and/or t_i computed by the physical state
control purpose information computation apparatus according to
claim 2, I_i, s_i and/or t_i corresponding to time divisions i.
27. A physical state controller which controls a physical state of
a control-processing-object material on the basis of physical state
control ranges, I_i, s_i and/or t_i computed by the physical state
control purpose information computation apparatus according to
claim 3, I_i, s_i and/or t_i corresponding to time divisions i.
28. A physical state controller which controls a physical state of
a control-processing-object material on the basis of physical state
control ranges, I_i, s_i and/or t_i computed by the physical state
control purpose information computation apparatus according to
claim 4, I_i, s_i and/or t_i corresponding to time divisions i.
29. A physical state controller which controls a physical state of
a control-processing-object material on the basis of physical state
control ranges, I_i, s_i and/or t_i computed by the physical state
control purpose information computation apparatus according to
claim 5, I_i, s_i and/or t_i corresponding to time divisions i.
30. A physical state controller which controls a physical state of
a control-processing-object material on the basis of physical state
control ranges, I_i, s_i and/or t_i computed by the physical state
control purpose information computation apparatus according to
claim 6, I_i, s_i and/or t_i corresponding to time divisions i.
31. A physical state controller which controls a physical state of
a control-processing-object material on the basis of physical state
control ranges, I_i, s_i and/or t_i computed by the physical state
control purpose information computation apparatus according to
claim 7, I_i, s_i and/or t_i corresponding to time divisions i.
32. A physical state controller which controls a physical state of
a control-processing-object material on the basis of physical state
control ranges, I_i, s_i and/or t_i computed by the physical state
control purpose information computation apparatus according to
claim 8, I_i, s_i and/or t_i corresponding to time divisions i.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of. Japanese patent
application serial number 2003-115246, filed Apr. 21, 2003, which
is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a physical state control
purpose information computation apparatus, a physical state control
purpose information computation method, a physical state control
purpose information computation program and a physical state
controller for controlling a control-processing-object material
with respect to a physical state of the material over a
predetermined control time period under control conditions in
consecutive time divisions into which the predetermined control
time period is divided. Typically, the present invention relates to
a physical state control purpose information computation apparatus,
a physical state control purpose information computation method, a
physical state control purpose information computation program and
a physical state controller applied to a continuous annealing
process in the steel industry.
[0004] Processes exist in which materials of different kinds are
connected in series and the train of the materials is conveyed on a
line to sequentially undergo heat treatment. Such processes are
typified by a continuous annealing process in steel manufacture.
Ordinarily, an allowable temperature range (upper limit, lower
limit) and a processing time are determined with respect to each of
different materials, and it is necessary for an apparatus for
performing heat treatment to change controlled temperatures so that
the temperature of each material is within the temperature range.
The temperature increase and decrease rates in the apparatus are
determined within certain limits.
[0005] In obtaining temperature transitions satisfying conditions
according to temperature ranges with respect to materials, it is
important to determine a suitable order (sequence) in which the
materials are caused to flow on a line. To know whether temperature
transitions satisfying conditions according to the temperature
ranges can be made with respect to a sequence, it is necessary to
evaluate the temperature transitions with respect to the sequence,
that is, it is necessary to evaluate whether temperature
transitions are possible such that no deviations from the
temperature ranges occur (or what amount of deviation is
allowable). Evaluations of temperature transitions thus obtained
are reflected in total evaluations of sequences of materials
(including evaluations of other restrictions) and used for the
purpose of determining a suitable one of the sequences. Target
temperature transitions finally obtained can be used as a
temperature increasing and reducing schedule in the apparatus for
heat treatment.
[0006] In conventional continuous annealing processes, finding a
sequence capable of satisfying conditions according to certain
temperature ranges has been intuitively performed by an expert (a
master or a skilled person) on an empirical basis. A method of
finding a suitable order of materials to be annealed,
conventionally performed by experts, will be described concretely.
For example, a displayable editable table is prepared on a screen
of a PC (personal computer) by a spreadsheet program such as Excel
(a registered trademark of Microsoft Corporation). In the table,
materials to be annealed are related to rows (records) and the
widths and thicknesses of the materials to be annealed, temperature
range codes and other attribute items are related to columns
(fields). The temperature range codes are numeric values, e.g., 75,
76, 86, 87, 88 . . . , and an expert grasps "75" as a temperature
range [240.degree. C.-280.degree. C.] and "76" as a temperature
range [260.degree. C.-310.degree. C.], for example. Also, the
expert roughly grasps the degree of proximity between 75 and 76,
between 86 and 87, and so on, and determines in his/her thought a
sequence such that the adjacent temperature ranges overlap one
another while considering other restrictions. In an ordinary
steelwork, a plurality of lines (e.g., several ten lines) exist on
which processes are simultaneously executed in parallel with each
other, and an expert determines in which sequences on lines each of
items to be annealed should be included. In the case where a need
to produce an item at an urgent request arises and where the item
at the urgent request is inserted in a predetermined line with
priority, it is necessary to reconsider the sequence following the
inserted article.
[0007] 2. Description of the Related Art
[0008] Patent Document 1 discloses a batch annealing process with
respect to a cast product. In the batch annealing process, a
determination reference temperature transition curve is formed on
the basis of an atmosphere temperature transition tendency
according to an empirical rule with respect to a self-annealing box
and atmosphere temperatures suitable for annealing, and actual
atmosphere temperatures in the self-annealing box at a plurality of
points in time in a self-annealing process are measured. The
quality of annealing is determined by checking the measured
temperatures against the determination reference temperature
transition curve.
[0009] Published Unexamined Patent Application No. 11-291021
[0010] If temperature transitions satisfying conditions according
to temperature ranges are possible, it is necessary to obtain such
transitions (of a zero temperature deviation cost). However, if it
is impossible to satisfy conditions according to the ranges, it is
not necessary to obtain temperature transitions (of a minimum
temperature deviation cost) by strict calculation. Finding
temperature transitions satisfying conditions according to
temperature ranges by changing the sequence is essentially
preferable. Also, since there is a substantially high possibility
of a schedule posterior with respect to time being changed
afterward, it is sufficient in ordinary cases to satisfy
temperature range conditions with respect to materials preceding in
time with priority. With respect to items to be annealed, it is
preferable to avoid changing the temperature during annealing from
the viewpoint of maintaining the quality. Since there is a
possibility of a sequence of materials coming after in time being
changed, for example, due to occurrence of a need to process an
additional item at an urgent request, it is desirable to avoid
changing the temperature as long as a point in time at which it
becomes impossible to satisfy temperature range conditions for
items to be subsequently annealed in the order or to reach an end
temperature is not reached.
[0011] In the conventional method of formation of a sequence by an
expert, it is difficult for an expert to accurately determine, with
respect to a sequence formed as an order of a plurality of
materials to be presently annealed, whether temperature control of
the entire sequence can be actually executed under temperature
increase and decrease rate restrictions so as to satisfy
temperature range conditions with respect to the materials to be
annealed. Also, it is difficult to immediately predict when
annealing on a material probable to come at a position closer to
the end of an order of materials to be annealed will end.
[0012] Patent Document 1 does not present or suggest any algorithms
for determination as to (a) whether, in a continuous annealing
process, with respect to a sequence of steel sections in which
steel sections to be annealed have different upper and lower limit
temperatures in corresponding annealing periods, temperature
control can be executed so as to satisfy conditions according to
the upper and lower limit temperatures of each steel section to be
annealed (hereinafter referred to simply as "temperature range
conditions" as occasion demands), and (b), under a demand for
minimizing variation in temperature in each steel section to be
annealed, which is desirable from the viewpoint of improving the
quality of the steel section to be annealed, how concrete
controlled temperature transitions should be made with respect to
the sequence of steel sections to be annealed to meet the demand
while satisfying the temperature range conditions.
[0013] A process is conceivable in which a temperature transition
cost is suitably defined with respect to the degree of deviation
from a temperature range and temperature transitions of the lowest
cost are obtained by a dynamic programming technique with respect
to possible temperature ranges. To perform this process, however,
there is a need to first discretize temperatures in ranges through
which transitions can be made. This discretization is
time-consuming and also entails a problem in terms of accuracy. If
discretization is finely performed to obtain temperature values in
wider ranges to improve the accuracy, the efficiency is
reduced.
[0014] A first object of the present invention is to provide a
physical state control purpose information computation apparatus, a
physical state control purpose information computation method, a
physical state control purpose information computation program and
a physical state controller capable of efficiently executing
processing for computation of information as to whether control of
a physical state of a control-processing-object material satisfying
physical state range conditions with respect to time divisions is
actually possible in the case where a limit heightening rate and a
limit lowering rate exist and where the physical state range
condition is determined with respect to each time division in a
control time period.
[0015] A second object of the present invention is to provide a
physical state control purpose information computation apparatus, a
physical state control purpose information computation method, a
physical state control purpose information computation program and
a physical state controller capable of efficiently computing a
concrete process of transition of a physical state in which
variation in the physical state in each of time divisions is
limited, and also having the capability according to the first
object.
[0016] A third object of the present invention is to provide a
physical state control purpose information computation apparatus, a
physical state control purpose information computation method, a
physical state control purpose information computation program and
a physical state controller capable of efficiently computing a
concrete process of transition of a physical state such that
physical states of a control-processing-object material at a
beginning time and an ending time in a control time period coincide
with a given value, and also having the capability according to the
second object.
[0017] A fourth object of the present invention is to provide a
physical state control purpose information computation apparatus, a
physical state control purpose information computation method, a
physical state control purpose information computation program and
a physical state controller suitable for annealing of steel, and
also having the capability according to the third object.
SUMMARY OF THE INVENTION
[0018] In a physical state controller using information computed by
a first physical state control purpose information computation
apparatus and method, a control time period of a finite length to
be used is divided into a plurality of consecutive time divisions.
The physical state controller controls a physical state of a
control-processing-object material. A limited physical state range
relating to the physical state of the control-processing-object
material is set in each time division. The physical state
controller changes the physical state of the
control-processing-object material at a rate within the
corresponding limit control rate range and simultaneously controls
the physical state of the control-processing-object material so
that the physical state of the control-processing-object material
is within the limited physical state range in the time
division.
[0019] The first physical state control purpose information
computation apparatus of the present invention has the following
means:
[0020] time-division-basis reachable physical state range
computation means of computing a reachable physical state range
reachable by the time the given time division ends on the basis of
the physical state control range at the beginning of the given time
division and the limit control rates of the physical state
controller;
[0021] time-division-basis physical state control range computation
means of computing a physical state control range at the beginning
of the time division next to the given time division on the basis
of the reachable physical state range at the end of the given time
division and the limited physical state range in the next time
division; and
[0022] overall physical state control range computation means of
designating the time divisions in order from the first time
division to the last time division in the control time period and
making each of the time-division-basis reachable physical state
range computation means and the time-division-basis physical state
control range computation means repeat executing its processing to
obtain physical state control ranges at the beginnings of all the
time divisions.
[0023] The first physical state control purpose information
computation method of the present invention has the following
steps:
[0024] a time-division-basis reachable physical state range
computation step of computing a reachable physical state range
reachable by the time the given time division ends on the basis of
the physical state control range at the beginning of the given time
division and the limit control rates of the physical state
controller;
[0025] a time-division-basis physical state control range
computation step of computing a physical state control range at the
beginning of the time division next to the given time division on
the basis of the reachable physical state range at the end of the
given time division and the limited physical state range in the
next time division; and
[0026] an overall physical state control range computation step of
designating the time divisions in order from the first time
division to the last time division in the control time period and
repeating executing each of the time-division-basis reachable
physical state range computation step and the time-division-basis
physical state control range computation step to obtain physical
state control ranges at the beginnings of all the time
divisions.
[0027] According to a second physical state control purpose
information computation apparatus and method, information to be
used by a physical state controller in which a control time period
of a finite length being divided into a plurality of consecutive
time divisions, and which controls a physical state of a
control-processing-object material on the basis of conditions
relating to the physical state of the control-processing-object
material in each of the time divisions through the entire control
time period is computed. Definitions shown below are given.
Information about n, b, e, LL_i, LH_i, D, and U is given. Each
index on the right-hand side of represents a number.
[0028] (a1) n: the total number of time divisions constituting the
control time period
[0029] (a2) i: the number of each time division in the control time
period when the time divisions are successively assigned numbers 1,
2, . . . , n in order from the first time division in'time
series
[0030] (a3) b: the value of the physical state of the
control-processing-object material at the beginning of the number-1
time division
[0031] (a4) e: the value of the physical state of the
control-processing-object material at the end of the number-n time
division
[0032] (a5) LL_i: a lower limit value of the physical state of the
control-processing-object material in the number-i time
division
[0033] (a6) LH_i: an upper limit value of the physical state of the
control-processing-object material in the number-i time
division
[0034] (a17) Li=[LL_i, LH_i], L_(n+1)=[LL_n, LH_n]
[0035] (a8) D: a limit heightening rate when the physical state of
the control-processing-object material is heightened
[0036] (a9) U: a limit lowering rate when the physical state of the
control-processing-object material is lowered
[0037] (a10)*: a multiplication operator
[0038] (a11) T_i: the length of the number-i time division
[0039] (a12) IL_i: a lower limit of the physical state of the
control-processing-object material reachable by the time the
number-i time division begins
[0040] (a13) IH_i: an upper limit of the physical state of the
control-processing-object material reachable by the time the
number-i time division begins
[0041] (a14) I_i=[IL_i, IH_i], I.sub.--1=[b, b]=b
[0042] (a15) Xi=[IL i-D*T_i, IH_i+U*T_i]
[0043] (a16) Y_i=X_i L_i when X_i L_i.sup.1 f
[0044] (a17)Y_i=X_i when X_i L_i=f
[0045] (a18) I_(i+1)=Y_i L_(i+1) when Y_i L_(i+1).sup.1f
[0046] (a19) I_(i+1)=Y_i when Y_i L_(i+1)=f.
[0047] A second physical state control purpose information
computation apparatus of the present invention has the following
means:
[0048] first processing means of computing X_i from I_i on the
basis of the above (a15) with respect to a given i;
[0049] second processing means of computing Y_i on the basis of the
result of computation by the first processing means and the above
(a16) and (a17) with respect to the given i;
[0050] third processing means of computing I_(i+1) on the basis of
the result of computation by the second processing means and the
above (a18) and (a19) with respect to the given i;
[0051] fourth processing means of storing, as information, I_(i+1),
i.e., the result of computation by the third processing means, with
respect to the given i; and
[0052] first number designation means of making each of the first
to fourth processing means execute its processing with respect to
the values of i in ascending order from i=1 to i=n.
[0053] A second physical state control purpose information
computation method of the present invention has the following
steps:
[0054] a first processing step of computing X_i from I_i on the
basis of the above (a15) with respect to a given i;
[0055] a second processing step of computing Y_i on the basis of
the result of computation in the first processing step and the
above (a16) and (a17) with respect to the given i;
[0056] a third processing step of computing I_(i+1) on the basis of
the result of computation in the second processing step and the
above (a18) and (a19) with respect to the given i;
[0057] a fourth processing step of storing, as information,
I_(i+1), i.e., the result of computation in the third processing
step, with respect to the given i; and
[0058] a first number designation step of executing each of the
first to fourth processing steps with respect to the values of i in
ascending order from i=1 to i=n.
[0059] Further definitions are given as shown below.
[0060] (b1) s.sub.--1=b
[0061] (b2) s_(i+1)=s_i when s_i I_(i+1)
[0062] (b3) s_(i+1)=IL_(i+1) when s_i<IL_(i+1)
[0063] (b4) s_(i+1)=IH_(i+1) when s_i>IH_(i+1).
[0064] A third physical state control purpose information
computation apparatus of the present invention has the same means
as those of the second physical state control purpose information
computation apparatus and the following other additional means:
[0065] fifth processing means of computing s_(i+1) on the basis of
the above (b2) to (b4) with respect to the given i;
[0066] sixth processing means of storing, as information, s_(i+1),
i.e., the result of computation by the fifth processing means, with
respect to the given i; and
[0067] second number designation means of making each of the fifth
and sixth processing means execute its processing with respect to
the values of i in ascending order from i=1 to i=n-1.
[0068] A third physical state control purpose information
computation method of the present invention has the same steps as
those of the second physical state control purpose information
computation method and the following other additional steps:
[0069] a fifth processing step of computing s_(i+1) on the basis of
the above (b2) to (b4) with respect to the given i;
[0070] a sixth processing step of storing, as information, s_(i+1),
i.e., the result of computation in the fifth processing step, with
respect to the given i; and
[0071] a second number designation step of executing each of the
fifth and sixth processing steps with respect to the values of i in
ascending order from i=1 to i=n-1.
[0072] Further definitions are given as shown below.
[0073] (c1) t_(n+1)=e,
[0074] (c2) Z_i (:=[ZL_i, ZH_i])=[t_(i+1)-U*T_i, t_(i+1)+D*T_i]
[0075] (c3) t_i=s_i when s_i Z_i
[0076] (c4) t_i=ZL_i when s_i<ZL_i
[0077] (c5) t_i=ZH_i when s_i>ZH_i.
[0078] A fourth physical state control purpose information
computation apparatus of the present invention has the same means
as those of the third physical state control purpose information
computation apparatus and the following other additional means:
[0079] seventh processing means of computing Z_i from t_(i+1) on
the basis of the above (c2) with respect to the given i;
[0080] eighth processing means of computing t_i on the basis of the
result of computation by the seventh processing means and the above
(c3) to (c5) with respect to the given i;
[0081] ninth processing means of storing, as information, t_i,
i.e., the result of computation by the eighth processing means,
with respect the given i; and
[0082] third number designation means of making each of the seventh
to ninth processing means execute its processing with respect to
the values of i in descending order from i=n to i=1.
[0083] A fourth physical state control purpose information
computation method of the present invention has the same steps as
those of the third physical state control purpose information
computation method and the following other additional steps:
[0084] a seventh processing step of computing Z_i from t_(i+1) on
the basis of the above (c2) with respect to the given i;
[0085] an eighth processing step of computing t_i on the basis of
the result of computation in the seventh processing step and the
above (c3) to (c5) with respect to the given i;
[0086] a ninth processing step of storing, as information, t_i,
i.e., the result of computation in the eighth processing step, with
respect the given i; and
[0087] a third number designation step of executing each of the
seventh to ninth processing steps with respect to the values of i
in descending order from i=n to i=1.
[0088] The second physical state control purpose information
computation apparatus and method can be used in combination with a
physical state control purpose information computation apparatus
and method which are different from the second and fourth physical
state control purpose information computation apparatuses and
methods, and in which series s_i and series t_i are computed from
series L_i.
[0089] The third physical state control purpose information
computation apparatus and method can be used in combination with a
physical state control purpose information computation apparatus
and method which are different from the fourth physical state
control purpose information computation apparatus and method, and
in which series t_i is computed from series s_i.
[0090] After computation of series I_i, s_i, and t_i with respect
to the entire control time period in which the n number of time
divisions exist in numbered order has been completed by the first
to fourth physical state control purpose information computation
apparatuses and methods, control based on the computed values is
started. When a control-processing-object material to be controlled
with priority appears thereafter, control for inserting the
control-processing-object material to be controlled with priority
before the control-processing-object material to be next processed
in the original schedule (assumed to have a number k+1) may be
executed. When such insertion control is executed, the inserted
control-processing-object material is assigned a number k; numbers
k, k+1, . . . , n are changed into numbers 1, 2, . . . , n-k; n-k
is newly set as n; and series I_i, s_i, and t_i are recomputed by
the first to fourth physical state control purpose information
computation apparatuses and methods.
[0091] To the above-described physical state control purpose
information computation apparatus and method, one of items
described below or a combination of any of the items described
below may be added.
[0092] The control-processing-object material is one of a solid, a
liquid and a gas, or a combination of any of the solid, liquid and
gas.
[0093] The physical state is a dynamic state, an optical state, a
thermodynamic state (including a temperature state) or an
electromagnetic state.
[0094] The control-processing-object material is a metal and the
physical state is temperature.
[0095] The metal is steel to be annealed. The steel to be annealed
is formed as a continuous member in which a plurality of lengthwise
sections having different annealing temperature upper and lower
limits are connected in series in the direction of movement, which
is moved at a constant speed, and which undergoes annealing at a
predetermined position in the direction of movement. LH_i and LL_i
correspond to the upper limit temperature and the lower limit
temperature in annealing on the number-i lengthwise section of the
continuous member.
[0096] A physical state control purpose information computation
program of the present invention makes a computer function as each
of the means in one of the above-described physical state control
purpose information computation apparatuses, or a physical state
control purpose information computation program of the present
invention makes a computer execute each of the steps in one of the
above-described physical state control purpose information
computation methods.
[0097] A physical state controller of the present invention
controls a physical state of a control-processing-object material
on the basis of physical state control ranges, I_i, s_i and/or t_i
computed by one of the above-described physical state control
purpose information computation apparatuses, I_i, s_i and/or t_i
corresponding to time divisions i.
BRIEF DESCRIPTION OF THE DRAWINGS
[0098] So that the manner in which the above recited features of
the present invention can be understood in detail, a more
particular description of the invention, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered limiting of
its scope, for the invention may admit to other equally effective
embodiments.
[0099] FIG. 1 is a diagram schematically, showing a
steel-manufacturing annealing apparatus;
[0100] FIG. 2 is a diagram showing temperature ranges in time
divisions on a temperature control schedule executed on an
annealing object steel band in the steel-manufacturing annealing
apparatus shown in FIG. 1;
[0101] FIG. 3 is a diagram showing reachable temperature regions
obtained by using Process 1 with respect to the temperature
restrictions shown in FIG. 2;
[0102] FIG. 4 is a diagram showing transitions of target
temperature t_i based on Process 2;
[0103] FIG. 5 is a diagram schematically showing the relationship
between restriction temperatures [LL_i, LH_i] and reachable
temperatures I_i in the time divisions corresponding to the
annealing object steel band;
[0104] FIG. 6 is a diagram showing the relationship between
reachable temperatures I_i and mark temperatures s_i;
[0105] FIG. 7 is a diagram showing the relationship between limit
rates U and D, mark temperature s_i and target temperature t_i;
[0106] FIG. 8 is a diagram for explaining the assumption that the
difference is not large;
[0107] FIG. 9 is a diagram for explaining the relationship between
a region R and a reachable temperature regions;
[0108] FIG. 10 is a functional block diagram of a physical state
control purpose information computation apparatus;
[0109] FIG. 11 is a functional block diagram of a physical state
control purpose information computation apparatus having additional
functions in comparison with the physical state control purpose
information computation apparatus shown in FIG. 10;
[0110] FIG. 12 is a functional block diagram of a physical state
control purpose information computation apparatus having additional
functions in comparison with the physical state control purpose
information computation apparatus shown in FIG. 11;
[0111] FIG. 13 is a flowchart of a physical state control purpose
information computation method;
[0112] FIG. 14 is a flowchart of a physical state control purpose
information computation method having additional processing in
comparison with the physical state control purpose information
computation method shown in FIG. 13;
[0113] FIG. 15 is a flowchart of a physical state control purpose
information computation method having additional processing in
comparison with the physical state control purpose information
computation method shown in FIG. 14;
[0114] FIG. 16 is a diagram of the configuration of hardware for
executing a program;
[0115] FIG. 17 is a functional block diagram of another physical
state control purpose information computation apparatus; and
[0116] FIG. 18 is a flowchart of another physical state control
purpose information computation method.
DETAILED DESCRIPTION
[0117] The present invention will be described concretely with
respect to a mode of implementation and an embodiment thereof.
Needless to say, the present invention is not limited to the mode
of implementation and embodiment, and various changes in the
described invention may be made without departing from the gist of
the invention.
[0118] Various symbols used for description are first defined.
Information about n, b, e, LL_i, LH_i, D, and U are given. Each
index on the right-hand side of "_" represents a number. Symbol f
represents an empty set. A control time period of a finite length
is divided into a plurality-of consecutive time divisions, and a
physical state of a control-processing-object material is
controlled on the basis of conditions relating to the physical
state of the control-processing-objec- t material in each of the
time divisions through the entire control time period.
[0119] (a1) n: the total number of time divisions constituting a
control time period
[0120] (a2) i: the number of each time division in the control time
period when the time divisions are successively assigned numbers 1,
2, . . . , n in order from the first time division in time
series
[0121] (a3) b: the value of the physical state of the
control-processing-object material at the beginning of the number-1
time division
[0122] (a4) e: the value of the physical state of the
control-processing-object material at the end of the number-n time
division
[0123] (a5) LL_i: a lower limit value of the physical state of the
control-processing-object material in the number-i time
division
[0124] (a6) LH_i: an upper limit value of the physical state of the
control-processing-object material in the number-i time
division
[0125] (a7) L_i=[LL_i, LH_i], L_(n+1)=[LL_n, LH_n]
[0126] (a8) D: a limit heightening rate when the physical state of
the control-processing-object material is heightened
[0127] (a9) U: a limit lowering rate when the physical state of the
control-processing-object material is lowered
[0128] (a10) *: a multiplication operator
[0129] (a11) T_i: the length of the number-i time division
[0130] (a12) IL_i: a lower limit of the physical state of the
control-processing-object material reachable by the time the
number-i time division begins
[0131] (a13) IH_i: an upper limit of the physical state of the
control-processing-object material reachable by the time the
number-i time division begins
[0132] (a14) I_i=[LL_i, IH_i], I.sub.--1=[b, b]=b
[0133] (a15) X_i=[IL_i-D*T_i, IH_i+U*T_i]
[0134] (a16) Y_i=X_i L_i when X_i L_i.sup.1 f
[0135] (a17) Y_i=X_i when X_i L_i=f
[0136] (a18) I_(i+1)=Y_i L_(i+1) when Y_i L_(i+1).sup.1f
[0137] (a19) I_(i+1)=Y_i when Y_i L_(i+1)=f
[0138] (b1) s.sub.--1=b
[0139] (b2) s_(i+1)=s_i when s_i I_(i+1)
[0140] (b3) s_(i+1)=IL_(i+1) when s_i<IL_(i+1)
[0141] (b4) s_(i+1)=IH_(i+1) when s_i>IH_(i+1)
[0142] (c1) t_(n+1)=e
[0143] (c2) Z_i (:=[ZL_i, ZH_i])=[t_(i+1)-U*T_i, t_(i+1)+D*T_i]
[0144] (c3) t_i=s_i when s_i Z_i
[0145] (c4) t_i=ZL_i when s_i<ZL_i
[0146] (c5) t_i=ZH_i when s_i>ZH_i
[0147] FIG. 1 is a diagram schematically showing a
steel-manufacturing annealing apparatus 10. The steel-manufacturing
annealing apparatus 10 is an example of application of the physical
state control purpose information computation apparatus of the
present invention to annealing in steel manufacture. The
steel-manufacturing annealing apparatus 10 includes a temperature
control apparatus 11 of a tunnel structure. Annealing object steel
band 12 is a lengthwise band-like member extending in the direction
of movement indicated by the arrow in FIG. 1. The annealing object
steel band 12 moves at a constant speed v in the direction of the
arrow, enters the temperature control apparatus 11 through an inlet
13, and exits from the temperature control apparatus 11 through an
outlet 14. The annealing object steel band 12 is formed of a train
of a plurality of different kinds of annealing object steel band
sections in which each adjacent pair of sections is connected in
the direction of movement by welding. The annealing object steel
band 12 typically has a thickness of 0.1 mm and a width of 1 m. The
temperature control apparatus 11 is controlled so that the
atmosphere temperature at a predetermined position in the direction
of movement of the annealing object steel band 12, typically the
atmosphere temperature at the outlet 14 is within temperature
ranges corresponding to the annealing object steel band sections
which pass through the apparatus 11.
[0148] In the steel-manufacturing annealing apparatus 10, the
above-described n, b, e, LL_i, D and U are defined by limiting
their concepts as described below. The annealing object steel band
12 is assumed to be an annealing object steel band of a finite
length on which temperature control scheduling is to be presently
performed. The annealing object steel band sections constituting
the annealing object steel band 12 are successively assigned
numbers 1, 2, . . . from the one coming first in the direction of
movement. The annealing object steel band 12 has annealing object
steel band sections m.sub.--1, m.sub.--2, . . . in the order from
the one coming first in the direction of movement. If the length of
the annealing object steel band section m_i is R_i, R_i=v.times.T_i
since the annealing object steel band 12 is moved at a constant
speed v.
[0149] n: the total number of annealing object steel band sections
in the annealing object steel band 12
[0150] b: the temperature at the time when control on the annealing
object steel band 12 is started
[0151] e: the temperature at the time when control on the annealing
object steel band 12 ends
[0152] LL_i: an upper limit temperature in temperature control on
the ith annealing object steel band section
[0153] LH_i: a lower limit temperature in temperature control on
the ith annealing object steel band section
[0154] D: a limit temperature increase rate in temperature control
on the annealing object steel band 12
[0155] U: a limit temperature decrease rate in temperature control
on the annealing object steel band 12
[0156] Restrictions in the case of application of the present
invention to temperature control on the annealing object steel band
12 in which a predetermined number, n, of annealing object steel
sections are successively arranged in a row are as described below.
A series of target temperatures t_i described below with reference
to FIG. 4 as a series of temperatures in the case of application of
the present invention to temperature control on the annealing
object steel band 12 satisfies the following restrictions.
[0157] (1) It is required that controlled temperature transitions
be made within the range between the limit increase rate U and the
limit decrease rate D.
[0158] (2) It is required that the controlled temperature start and
end values b and e be linked. (It is assumed that the difference
between b and e is not so large that b and e cannot be linked by
limit rates U and D.)
[0159] (3) It is required that the controlled temperature with
respect to each annealing object steel section be maintained within
the range between the upper and lower limits with front priority as
unfailingly as possible except when conformance to the restrictions
(1) and (2) is made impossible.
[0160] (4) It is required that controlled temperature transitions
be fixed as uniformly as possible except when conformance to the
restrictions (1) to (3) is made impossible.
[0161] The reason for front priority in (3) is that the possibility
of a sequence relating to a posterior part of a schedule being
changed by insertion of an annealing object steel section at an
urgent request is high at the time of actual control according to
the posterior part, and that importance is therefore attached to a
schedule part closer to the present time.
[0162] FIG. 2 shows temperature ranges (also called temperature
restrictions) in time divisions on a temperature control scheduling
executed on the annealing object steel band 12 in the
steel-manufacturing annealing apparatus 10 shown in FIG. 1. The
temperature control apparatus 11 has n number of annealing object
steel band sections m.sub.--1, m.sub.--2, . . . , m_i, . . . , m_n
connected in series in the direction of movement. Referring to FIG.
2, since the annealing object steel band 12 is passed through the
temperature control apparatus 11 at the constant speed v, the time
T.sub.--1, T.sub.--2, . . . , T_i, . . . , T_n required to pass
each of the annealing object steel band sections m.sub.--1,
m.sub.--2, . . . , m_i, . . . , m_n through a predetermined
portion, e.g., the outlet 14 of the temperature control apparatus
11 is proportional to the length R.sub.--1, R.sub.--2, . . . R_i, .
. . , R_n of the annealing object steel band section in the
direction of movement. The temperature control apparatus 11
performs temperature control on each annealing object steel band
section so that the atmosphere temperature at a predetermined
portion, e.g., the outlet 14 of the temperature control apparatus
11 is within the temperature range L_i=[LL_i, LH_i] corresponding
to the annealing object steel band section. That is, each annealing
object steel band section m_i is not subjected to the atmosphere
temperature in the temperature range L_i=[LL_i, LH_i] corresponding
to it when it enters the inlet 13, but the atmosphere is controlled
by the temperature control apparatus 11 so that the atmosphere
temperature is in the temperature range L_i=[LL_i, LH_i] before or
when the annealing object steel band section reaches the outlet 14.
In a typical example of numeric values in the schedule shown in
FIG. 2, the time period from the start to the end of temperature
control is about one month; the annealing temperature is about 400
to 600.degree. C.; the temperature range L_i is 50.degree. C.; and
one time division T_i is about several ten minutes.
[0163] A method of determining mark temperatures (series s_i will
be referred to as "mark temperatures") in the steel-manufacturing
annealing apparatus 10 can be roughly divided into two processes
described below. If temperatures to be given to the annealing
object steel band 12 by the temperature control apparatus 11 to
enable the annealing object steel band 12 to be suitably annealed
are referred to as "target temperatures", mark temperatures are
considered intermediate data for obtaining target temperatures.
[0164] Process 1: Computation of reachable temperature regions
(top.RTM. end)
[0165] Process 2: Computation of mark temperatures through the
regions in Process 1 (end.RTM. top)
[0166] In Processes 1 and 2, a series of mark temperatures s_i and
a series of target temperatures t_i are respectively computed.
Series s_i is computed by considering the above-described
restrictions (1), (3) and (4) in the case of application of the
present invention to temperature control on the annealing object
steel band 12, and series t_i is computed by considering the
restrictions (1), (2) and (4).
[0167] In Process 1, the ranges of temperatures reachable by
temperature transitions are successively obtained from the top to
the end of the sequence starting from a start temperature while
satisfying the restriction on the limit transition rates U and D.
In the restrictions on the ranges of temperatures of the annealing
object steel band sections, the restrictions on a front portion of
the sequence are obtained with priority without considering the
restrictions on a rear portion of the sequence. A region surrounded
by lines each connecting two of the upper and lower limits of each
adjacent pair of the reachable temperature ranges is referred to as
a reachable temperature region. FIG. 3 shows reachable temperature
regions obtained by using Process 1 with respect to the temperature
restrictions shown in FIG. 2. In Process 1, mark temperatures s_i
representing temperatures in the reachable ranges to which
transitions of the temperatures of the annealing object steel band
sections should be made are recorded to enable small-variation
temperature transitions to be obtained in Process 2. A concrete
example of the method of computing mark temperatures s_i will be
described below.
[0168] In Process 2, target temperatures t_i are successively
obtained from the end (i=n) to the top (i=1) of the sequence
starting from the end temperature e while satisfying the
restriction on the limit transition rates U and D. The target
temperatures t_i aim to follow the mark temperatures s_i obtained
in Process 1. If the reachable range I_i in Process 1 does not
deviate from the temperature range L_i and if it finally includes
the end temperature e, transitions satisfying the condition
according to the temperature range L_i can be made in the sequence.
In Process 2, in this case, no deviation of temperature transition
from each reachable range occurs and, therefore, it is ensured that
temperature transitions satisfying the temperature range conditions
can be obtained. FIG. 4 shows transitions of target temperatures
t_i on the basis of Process 2.
[0169] FIG. 5 schematically shows the relationship between
restriction temperatures [LL_i, LH_i] and reachable temperatures
I_i in the time divisions corresponding to the annealing object
steel band. Reachable temperatures I_i are computed on the basis of
equations (a15) to (a19) from i=1 to i=n in ascending order. From
the condition (a3), I.sub.--1 (=[IL.sub.--1, IH.sub.--1])=b.
[0170] FIG. 6 shows the relationship between reachable temperatures
I_i and mark temperatures s_i. Mark temperatures s_i are computed
on the basis of equations (b2) to (b4) from i=1 to i=n in ascending
order. FIG. 6(a) shows the relationship in the case of (b2), and
FIG. 6(b) shows the relationship in the case of (b3) or (b4).
[0171] In Process 2, target temperatures t_i are obtained from the
end to the top, i.e., from i=n to i=1 in descending order starting
from the end temperature e, so as to follow the target temperatures
obtained in Process 1 while satisfying the restriction on the limit
transition rates. FIG. 7 shows the relationship between the limit
rates U and D, mark temperature s_i and target temperature t_i.
FIG. 7(a) shows the relationship in the case of (c3), and FIG. 7(b)
shows the relationship in the case of (c4) or (c5). If the
difference between the end temperature and the start temperature is
so large that they cannot be linked even by a straight line having
gradients corresponding to the limit (U, D) of the temperature
transition rate (the meaning of this condition will be described
below in detail with reference to FIGS. 8 and 9), the target
temperature t.sub.--1 is not linked to the start temperature b.
However, it is assumed that the end temperature and the start
temperature do not differ so largely. The target temperature
approaches the reachable temperature region from the end
temperature at the limit rate. After entering the region, it links
with the start temperature without deviating out of the region. If
the end temperature e is included in the reachable region (that is,
e I_(n+1)), and if all the temperature reachable ranges are within
the temperature ranges (that is, oei: I_i L_i), temperature
transitions satisfying the temperature range conditions can be
made. From the way of setting the target temperature, it can be
understood that transitions of the temperature are made as uniform
as possible and that when the temperature is changed, it is changed
at a rate set to the temperature transition limit rate as closely
as possible. As processing influencing the efficiency of
computation, loop processing is performed only a number of times
twice the number n of the annealing object steel band sections (n
times in Process 1, and n times in Process 2).
[0172] It will be proved from FIGS. 8 and 9 that t_1 computed on
the basis of (c1) to (c5) is t.sub.--1=b. FIG. 8 is a diagram for
explaining the assumption that the difference between the start
temperature b and the end temperature e is not so-large that the
start temperature b and the end temperature e cannot be linearly
linked at a limit increase/decrease rate. That is, when two
straight lines having gradients corresponding to the temperature
limit increase rate U and the temperature limit decrease rate D are
drawn from b, e is contained in the region between the two lines
(hereinafter referred to as "region R").
[0173] FIG. 9 is a diagram for explaining the relationship between
the region R and the reachable temperature regions. It is apparent
that the region R contains the reachable temperature regions. All
target temperatures s_i are contained in the reachable temperature
regions, and are necessarily contained in the region R. Referring
to the equations for computation of target temperatures t_i, it can
be understood that if both t_(i+1) and s_i are contained in the
region R, t_i is also contained in the region R. All of
s.sub.--1=b, s.sub.--1, s.sub.--2, . . . , s_n are contained in the
region R. t_(n+1)=e is contained in the region R. It is shown by
induction that all of t_n, t_(n-1), . . . , t.sub.--2, t.sub.--1
are contained in the region R. Since the region R at the time of
starting is one point b, t.sub.--1=b.
[0174] FIG. 10 is a functional block diagram of a physical state
control purpose information computation apparatus 15. The same
definitions as (a1) to (a19) described above are given. The
physical state control purpose information computation apparatus
15, is not limited to the steel-manufacturing annealing apparatus
10. That is, a material on which the physical state control purpose
information computation apparatus 15 performs physical state
control may be, for example, one of a solid, a liquid and a gas, or
a combination of any of the solid, liquid and gas as well as the
annealing object steel band 12. The physical state is, for example,
a dynamic state, an optical state, a thermodynamic state
(comprising a temperature state), or an electromagnetic state.
[0175] In the physical state control purpose information
computation apparatus 15 shown in FIG. 10, a first processing means
16 computes X_i from I_i on the basis of (a15) with respect to the
given i. A second processing means 17 computes Y_i on the basis of
the result of computation by the first processing means 16 and
(a16) and (a17) with respect to the given i. A third processing
means 18 computes I_(i+1) on the basis of the result of computation
by the second processing means 17 and (a18) and (a19) with respect
to the given i. A fourth processing means 19 stores, as
information, I_(i+1), i.e., the result of computation by the third
processing means 18, with respect to the given i. A first number
designation means 20 makes each of the first to fourth processing
means 16 to 19 execute its processing with respect to the values of
i in ascending order from i=1 to i=n. The first to fourth
processing means 16 to 19 as a whole constitute an instruction
receiving means 21 for receiving instructions from the first number
designation means 20.
[0176] FIG. 11 is a functional block diagram of another physical
state control purpose information computation apparatus 15 having
the same functions as those of the physical state control purpose
information computation apparatus 15 shown in FIG. 10, and other
additional functions. The same definitions as (b1) to (b4)
described above are given. A fifth processing means 23 computes
s_(i+1) on the basis of (b2) to (b4). The fifth processing means 23
computes s_(i+1) on the basis of (b2) to (b4) with respect to the
given i. A sixth processing means 24 stores, as information,
s_(i+1), i.e., the result of computation by the fifth processing
means 23, with respect to the given i. A second number designation
means 25 makes each of the fifth and sixth processing means 23 and
24 execute its processing with respect to the values of i in
ascending order from i=1 to i=n-1. The fifth and sixth processing
means 23 and 24 as a whole constitute an instruction receiving
means 26 for receiving instructions from the second number
designation means 25.
[0177] FIG. 12 is a functional block diagram of another physical
state control purpose information computation apparatus 15 having
the same functions as those of the physical state control purpose
information computation apparatus 15 shown in FIG. 11, and other
additional functions. The same definitions as (c1) to (c5)
described above are given. A seventh processing means 30 computes
Z_i from t_(i+1) on the basis of (c2). An eighth processing means
31 computes t_i from Z_i and s_i on the basis of (c3) to (c5). A
ninth processing means 32 stores t_i as information. A third number
designation means 33 makes each of the seventh to ninth processing
means 30 to 32 execute its processing with respect to the values of
i in descending order from i=n to i=1.
[0178] Series t_i is formed in such a manner that the degree of
flatness of the controlled state in each time division is maximized
(t_i is made constant) while the conditions with respect to b, e,
U, D, and L_i are satisfied. According to the above description
with reference to FIG. 4, the controlled state or temperature is
increased or decreased from t_i to t_(i+1) as indicated by one
straight line in the time divisions i in which the controlled state
or temperature is not flat. However, the present invention is not
limited to this. In the present invention, the temperature in each
time division i may be changed according to one's need as indicated
by a curved line, a bent and curved line or the like as long as the
restrictions on the temperature t_i at the beginning of the time
division i and the temperature t_(i+1) at the end are satisfied. In
the case of temperature control on the annealing object steel band
12, etc., however, it is desirable from the viewpoint of
maintaining the quality that a change in temperature of each
annealing object steel band section be flat, i.e., small. There is
also a possibility of sudden occurrence of a need to insert an
additional item at an urgent request, i.e., a possibility of
t_(i+1) being changed. As a method for coping with this, a control
method is conceivable in which, for example, if the time division i
is comparatively long, the temperature is maintained at t_i until a
time close to a limit beyond which t_(i+1) in the next time
division i+1 cannot be attained under the restrictions on U and D,
that is, the temperature is maintained so that a change therein is
flat, and the temperature is changed at U or D in a closing period
in the time division i.
[0179] FIG. 13 is a flowchart of a physical state control purpose
information computation method. The same definitions as (a1) to
(a19) described above are given. The physical state control purpose
information computation method is not limited to an application to
temperature control on annealing object steel band sections
constituting an annealing object steel sequence, as in the case of
the physical state control purpose information computation
apparatus 15. That is, a material on which control is performed by
the physical state control purpose information computation method
may be, for example, one of a solid, a liquid and a gas, or a
combination of any of the solid, liquid and gas as well as the
annealing object steel. The physical state is, for example, a
dynamic state, an optical state, a thermodynamic state (comprising
a temperature state), or an electromagnetic state.
[0180] Referring to FIG. 13, in a first processing step S50, X_i is
computed from I_i on the basis of (a15) with respect to the given
i. In a second processing step S51, Y_i is computed on the basis of
the result of computation in the first processing step S50 and
(a16) and (a17) with respect to the given i. In a third processing
step S52, I_(i+1) is computed on the basis of the result of
computation in the second processing step S51 and (a18) and (a19)
with respect to the given i. In a fourth processing step S53,
I_(i+1), i.e., the result of computation in the third processing
step S52, is stored as information with respect to the given i. In
a first number designation step S54, the first to fourth processing
steps S51 to S53 are executed with respect to the values of i in
ascending order from i=1 to i=n.
[0181] FIG. 14 is a flowchart of another physical state control
purpose information computation method including the same
processing as that of the physical state control purpose
information computation method shown in FIG. 13, and other
additional processing. The same definitions as (b1) to (b4)
described above are given. In a fifth processing step S58, s_(i+1)
is computed on the basis of (b2) to (b4) with respect to the given
i. In a sixth processing step S59, s_(i+1), i.e., the result of
computation in the fifth processing step S58, is stored as
information with respect to the given i. In a second number
designation step S60, the fifth and sixth processing steps S58 and
S59 are executed with respect to the values of i in ascending order
from i=1 to i=n-1.
[0182] FIG. 15 is a flowchart of another physical state control
purpose information computation method including the same
processing as that of the physical state control purpose
information computation method shown in FIG. 14, and other
additional processing. The same definitions as (c1) to (c5)
described above are given. In a seventh processing step S63, Z_i is
computed from t_(i+1) on the basis of (c2) with respect to the
given i. In an eighth processing step S64, t_i is computed on the
basis of the result of computation in the seventh processing step
S63 and (c3) to (c5) with respect to the given i. In a ninth
processing step S65, t_i, i.e., the result of computation in the
eighth processing step S64, is stored as information with respect
to the given i. In a third number designation step S67, the seventh
to ninth processing steps S63 to S65 are executed with respect to
the values of i in descending order from i=n to i=1.
[0183] In the physical state control purpose information
computation apparatuses 15 and the physical state control purpose
information computation methods described with reference to FIGS.
10 to 15, technical items described below may be added or made
concrete singly or in any combination.
[0184] The control-processing-object material is one of a solid, a
liquid and a gas, or a combination of any of the solid, liquid and
gas.
[0185] The physical state is a dynamic state, an optical state, a
thermodynamic state or an electromagnetic state.
[0186] The control-processing-object material is a metal and the
physical state is temperature.
[0187] The metal is steel to be annealed. The steel to be annealed
is formed as a continuous member in which a plurality of lengthwise
sections having different annealing temperature upper and lower
limits are connected in series in the direction of movement, which
is moved at a constant speed, and which undergoes annealing at a
predetermined position in the direction of movement. LH_i and LL_i
correspond to the upper limit temperature and the lower limit
temperature in annealing on the number-i lengthwise section of the
continuous member.
[0188] FIG. 16 is a diagram of the configuration of hardware for
executing a program. The hardware shown in FIG. 16 is made to
function as the means in each of the physical state control purpose
information computation apparatuses 15 described with reference to
FIGS. 10 to 12 to execute a corresponding program. Alternatively,
the hardware shown in FIG. 16 is made to execute the steps in each
of the physical state control purpose information, computation
methods described with reference to FIGS. 13 to 15 to execute a
corresponding program. A CPU 71, a main storage unit 72 and an
input/output controller 73 are connected to a system bus 70. The
above-described means or steps can be executed as a program formed
as codes. The input/output controller 73 includes a hard disk
interface or the like. Various programs executed by the CPU 71 are
stored in a hard disk unit or the like. Each program is stored in
the main storage unit 72 before being executed by the CPU 71. The
CPU 71 executes the program by successively reading out instruction
lines from the main storage unit 72.
[0189] FIG. 17 is a functional block diagram of another physical
state control purpose information computation apparatus 80. The
following is the correspondence relationship between terms used for
the physical state control purpose information computation
apparatus 80 shown in FIG. 17 and a physical state control purpose
information computation method shown in FIG. 18 and the symbols in
the above-described definitions (a1) to (a19), (b1) to (b4), and
(c1) to (c5).
[0190] Limited physical state range in time division: [LL_i,
LH_i]
[0191] Limit control rate range of physical state controller: U,
D
[0192] Physical state control range at the beginning of time
division: [IL_i, IH_i]
[0193] Reachable physical state range: X_i
[0194] Physical state control mark value at the beginning of time
division: s_i
[0195] Physical state control target value: t_i
[0196] The physical state control purpose information computation
apparatus 80 has three blocks 81, 82, and 83. In a physical state
controller (not shown) using information computed by the physical
state control purpose information computation apparatus 80, a
control time period of a finite length is divided into a plurality
of consecutive time divisions. The physical state controller
controls a physical state of a control-processing-object material.
A limited physical, state range relating to the physical state of
the control-processing-object material is set in each time
division. The physical state controller changes the physical state
of the control-processing-object material at a rate within the
corresponding limit control rate range and simultaneously controls
the physical state of the control-processing-object material, so
that the physical state of the control-processing-object material
is within the limited physical state range in the time
division.
[0197] In the block 81, a time-division-basis reachable physical
state range computation means 88 computes a reachable physical
state range reachable by the time the given time division ends on
the basis of the physical state control range at the beginning of
the given time division and the limit control rates of the physical
state controller. A time-division-basis physical state control
range computation means 89 computes a physical state control range
at the beginning of the time division next to the given time
division on the basis of the reachable physical state range at the
end of the given time division and the limited physical state range
in the next time division. An overall physical state control range
computation means 90 designates the time divisions in order from
the first time division to the last time division in the control
time period to make each of the time-division-basis reachable
physical state range computation means 88 and the
time-division-basis physical state control range computation means
89 repeat executing its processing, thereby obtaining physical
state control ranges at the beginnings of all the time
divisions.
[0198] In the block 82, a time-division-basis physical state
control mark value computation means 93 computes a physical state
control mark value at the beginning of the time division next to
the given time division on the basis of the physical state control
mark value at the beginning of the given time division, the
physical state control range at the beginning of the next time
division and the limit control rates of the physical state
controller. An overall physical state control mark value
computation means 94 designates the time divisions in order from
the first time division to the last time division in the control
time period while being given the mark temperature at the beginning
of the control time period to make the time-division-basis physical
state control mark value computation means 93 repeat executing its
processing, thereby obtaining physical state control mark values at
the beginnings of all the time divisions.
[0199] In the block 83, a time-division-basis physical state target
value computation means 97 computes a physical state control target
value at the beginning of the time division immediately precedent
to the given time division on the basis of the physical state
control target value at the beginning of the given time division,
the physical state control mark value at the beginning of the
immediately preceding time division and the limit control rates of
the physical state controller. An overall physical state control
target value computation means 98 designates the time divisions in
order from the last time division to the first time division in the
control time period while being given the control target value at
the end of the control time period to make the time-division-basis
physical state control target value computation means repeat
executing its processing, thereby obtaining physical state control
target values at the beginnings of all the time divisions.
[0200] FIG. 18 is a flowchart of another physical state control
purpose information computation method. This physical state control
purpose information computation method has three blocks B101, B102,
and B103. In a physical state controller using information computed
by this physical state control purpose information computation
method, a control time period of a finite length is divided into a
plurality of consecutive time divisions. The physical state
controller controls a physical state of a control-processing-object
material. A limited physical state range relating to the physical
state of the control-processing-object material is set in each time
division. The physical state controller changes the physical state
of the control-processing-object material at a rate within the
corresponding limit control rate range and simultaneously controls
the physical state of the control-processing-object material so
that the physical state of the control-processing-object material
is within the limited physical state range in the time
division.
[0201] In the block B101, in a time-division-basis reachable
physical state range computation step S105, a reachable physical
state range reachable by the time the given time division ends is
computed on the basis of the physical state control range at the
beginning of the given time division and the limit control rates of
the physical state controller. In a time-division-basis physical
state control range computation step S106, a physical state control
range at the beginning of the time division next to the given time
division is computed on the basis of the reachable physical state
range at the end of the given time division and the limited
physical state range in the next time division. In an overall
physical state control range computation step S107, each of the
time-division-basis reachable physical state range computation step
S105 and the time-division-basis physical state control range
computation step S106 is repeatedly executed by designating the
time divisions in order from the first time division to the last
time division in the control time period, thereby obtaining
physical state control ranges at the beginnings of all the time
divisions.
[0202] In the block B102, in a time-division-basis physical state
control mark value computation step S108, a physical state control
mark value at the beginning of the time division next to the given
time division is computed on the basis of the physical state
control mark value at the beginning of the given time division, the
physical state control range at the beginning of the next time
division and the limit control rates of the physical state
controller. In an overall physical state control mark value
computation step S109, the time-division-basis physical state
control mark value computation step S108 is repeatedly executed by
designating the time divisions in order from the first time
division to the last time division in the control time period while
the mark temperature at the beginning of the control time period is
given, thereby obtaining physical state control mark values at the
beginnings of all the time divisions.
[0203] In the block B103, in a time-division-basis physical state
target value computation step S112, a physical state control target
value at the beginning of the time division immediately precedent
to the given time division is computed on the basis of the physical
state control target value at the beginning of the given time
division, the physical state control mark value at the beginning of
the immediately preceding time division and the limit control rates
of the physical state controller. In an overall physical state
control target value computation step S113, the time-division-basis
physical state control target value computation step is repeatedly
executed by designating the time divisions in order from the last
time division to the first time division in the control time period
while the control target value at the end of the control time
period are given, thereby obtaining physical state control target
values at the beginnings of all the time divisions.
[0204] According to the present invention, as described above,
information as to whether control of a physical state of a
control-processing-object material satisfying restrictions on a
limit heightening rate and a limit lowering rate and physical state
control range conditions with respect to time divisions can be
performed can be efficiently examined without using dynamic
programming. Also, a concrete process of transition of the physical
state in which the change in the physical state in each of time
divisions is limited can be presented and a physical state
transition process in which the physical state of the
control-processing-object material at the ending time in the
control time period coincides with a given value can be
presented.
[0205] While the foregoing is directed to embodiments of the
present invention, other and further embodiments of the invention
may be devised without departing from the basic scope thereof, and
the scope thereof is determined by the claims that follow.
[0206] Reference Numerals:
[0207] 10 . . . steel-manufacturing annealing apparatus
[0208] 11 . . . temperature control apparatus
[0209] 12 . . . annealing object steel band
[0210] 15 . . . physical state control purpose information
computation apparatus
[0211] 16 . . . first processing means
[0212] 17 . . . second processing means
[0213] 18 . . . third processing means
[0214] 19 . . . fourth processing means
[0215] 20 . . . first number designation means
[0216] 23 . . . fifth processing means
[0217] 24 . . . sixth processing means
[0218] 25 . . . second number designation means
[0219] 30 . . . seventh processing means
[0220] 31 . . . eighth processing means
[0221] 32 . . . ninth processing means
[0222] 33 . . . third number designation means
[0223] 80 . . . physical state control purpose information
computation apparatus
[0224] 88 . . . time-division-basis reachable physical state range
computation means
[0225] 89 . . . time-division-basis physical state control range
computation means
[0226] 90 . . . overall physical state control range computation
means
[0227] 93 . . . time-division-basis physical state control mark
value computation means
[0228] 94 . . . overall physical state control mark value
computation means
[0229] 97 . . . time-division-basis physical state target value
computation means
[0230] 98 . . . overall physical state control target value
computation means
* * * * *